RICE LAKE 311 Belt Scale Instruction Manual

: June 16, 2024
: RICE LAKE

Table of Contents

RICE LAKE 311 Belt Scale
Product Information
Introduction
Installation
Maintenance
- Dimensional Drawings
Specifications
List Parameters for Belt Scale
References
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RICE LAKE 311 Belt Scale

RICE-LAKE-311-Belt-Scale-product

Product Information

Specifications:

Model: MASTER 311, 311M, and 711
Installation Manual: Installation_Manual_BS311_V1, PN 170735

Introduction

The MASTER 311, 311M, and 711 Weighframes are designed to measure a continuous mass flow on a belt conveyor. These weighframes are composed of one or more load cells, a speed sensor/pickup, and integrator electronics. The MasterTM belt scale series is developed for various applications and conveyor types.
Please note that not every application is suitable for a belt scale, and it is recommended to consult with a Rice Lake Weighing Systems specialist to analyze the suitability for your specific application.
Safety is of utmost importance when using the MASTER weighframes. The product includes safety symbols to indicate potential hazards and necessary precautions.

Installation

Splice Box Installation
To install the splice box:

Open the packaging and locate the splice box.
Choose a suitable location for the splice box near the belt conveyor.
Securely mount the splice box using the provided screws.

Electrical Installation
To perform the electrical installation:

Ensure that power to the belt conveyor is turned off.
Connect the electrical cables according to the provided wiring diagram.
Double-check all connections for proper insulation and secure them tightly.

Commissioning
The commissioning process involves mechanical adjustments to ensure accurate weighing. Follow the steps below:

Make sure the belt conveyor is empty and stationary.
Adjust the weigh frame position to align with the belt conveyor.
Check and adjust the load cell alignment and tension.

Mechanical Adjustments
To make mechanical adjustments:

Loosen the screws holding the weigh frame in place.
Align the weigh frame with the belt conveyor and tighten the screws securely.
Check the load cell alignment and adjust if necessary.
Ensure proper tension in the load cell cables and adjust as needed.

Maintenance

Periodical Maintenance
To ensure the continued performance of the MASTER weighframes, regular maintenance is required. Perform the following periodical maintenance tasks:

Clean the weigh frame and remove any debris or buildup.
Inspect the load cells for any damage or wear and replace them if necessary.
Check the speed sensor/pickup for proper functioning and cleaning if needed.

FAQ (Frequently Asked Questions)

Q: Are technical training seminars available for the MASTER weighframes?
A: Yes, technical training seminars are available through Rice Lake Weighing Systems. Course descriptions and dates can be viewed at www.ricelake.com/training or obtained by calling 715-234-9171 and asking for the training department.
Q: Is Rice Lake Weighing Systems an ISO 9001 registered company?
A: Yes, Rice Lake Weighing Systems has been an ISO 9001 registered company since October 01, 2015.
Q: Where can I find manuals and warranty information for the MASTER weighframes?
A: Manuals can be viewed and downloaded from the Rice Lake Weighing Systems website at www.ricelake.com and www.ricelake.eu. Warranty information can be found on the website at www.ricelake.com/warranties.
Q: Are web-based video training sessions available for the MASTER weighframes?
A: Yes, Rice Lake continually offers web-based video training on a growing selection of product-related topics at no cost. Visit www.ricelake.com/webinars for more information.

Technical training seminars are available through Rice Lake Weighing Systems. Course descriptions and dates can be viewed at www.ricelake.com/training or obtained by calling 715-234-9171 and asking for the training department.

Rice Lake continually offers web-based video training on a growing selection of product-related topics at no cost. Visit www.ricelake.com/webinars.

Introduction

Belt scales measure a continuous mass flow, which is transported over a belt conveyor. A complete belt scale is composed of a weighframe, which contains one or more load cells, a speed sensor/pickup and the integrator electronics. Not every application is suited for a belt scale; this has to be analyzed by a Rice Lake Weighing Systems specialist. To achieve the optimum result, the Master™ belt scale series has been developed for a number of applications and for every type of conveyor.

Manuals can be viewed and downloaded from the Rice Lake Weighing Systems website at: www.ricelake.com and www.ricelake.eu
Warranty information can be found on the website at: www.ricelake.com/warranties.

Safety

Safety Symbol Definitions

DANGER Indicates an imminently hazardous situation that, if not avoided, will result in death or serious injury.
WARNING Indicates a potentially hazardous situation that, if not avoided, could result in death or serious injury, and includes hazards that are exposed when guards are removed.
CAUTION Indicates a potentially hazardous situation that, if not avoided, may result in minor or moderate injury.
Important Indicates information about procedures that, if not observed, could result in damage to equipment or corruption to and loss of data.

General Safety
Do not operate or work on this equipment unless you have read and understand the instructions and warnings in this manual. Failure to follow the instructions or heed the warnings could result in injury or death. Contact any Rice Lake Weighing Systems dealer for replacement manuals. Proper care is your responsibility.

WARNING
Failure to heed may result in serious injury or death.

Some procedures described in this manual require work inside the enclosure. These procedures are to be performed by qualified service personnel only.
Take all necessary safety precautions when installing the scale carriage including wearing safety shoes, protective eye wear and using the proper tools.
Keep hands, feet and loose clothing away from moving parts.
Do not approach a running conveyor from underneath.
Do not bend over a running conveyor.
Do not allow minors (children) or inexperienced persons to operate this unit.
Do not operate without all shields and guards in place.
Do not jump on the scale.
Do not use for purposes other than weight taking.
Do not place fingers into slots or possible pinch points.
Do not use any load-bearing component that is worn beyond 5 percent of the original dimension.
Do not use this product if any of the components are cracked.
Do not exceed the rated load limit of the unit.
Do not make alterations or modifications to the unit.
Do not remove or obscure warning labels.

Overview

The weigh frame model Master 311/711 Series is designed for medium and heavier applications in the process industry, where accuracy and/or legal approval is required.
The dimensions are extracted from the construction of the existing, or to-be-built, belt conveyor.

Theory of Operation
The material is carried by the belt and underlying rollers or idler stations. One or more of these idlers are mounted on the weigh frame and are used to weigh the material going across the belt. The material carried on the belt is weighed and the belt speed is measured. Both values (belt load and belt speed) are calculated in an integration function. The integrator totals and calculates the mass flow. These values are displayed and transmitted through outputs or other forms of communication to a control system or network.

For the operation, refer to the manual of the electronics installed.

Selection Criteria

Load cell capacity is calculated based on the maximum belt load plus the dead load of the weigh frame and the weight of the rollers. Contact Rice Lake Weighing Systems technical support for assistance.

Netload = (conveyor capacity / belt speed) x idler spacing
Gross load = net load + (idler weight + belt weight + mounting hardware)

Examples:

Netload = (20,000 lb (9,072 kg) per minute / 400 ft (122 m) per minute) x 4 ft (1.22 m) spacing
Netload = (50 lb (23 kg) per ft) x 4 ft (1.22 m) spacing
Netload = 200 lb (91 kg)
Gross load = 200 lb (91 kg) + (175 lb (79 kg) idler + 48 lb (22 kg) belt + 24 lb (11 kg) hardware)
Gross load = 447 lb (203 kg)

Calibration and Test Weight Device

Mounting points can be provided to apply static test weights. Test weights are used to test repeatability and the state of the belt scale after initial calibration.
To determine absolute accuracy, it is necessary to do a test with the material. For this procedure, refer to the manual of the electronics installed.

Installation

Installation procedures generally should be a combination of the end user’s best engineering practices in compliance with local codes and the manufacturer’s recommendations. To achieve maximum performance, the following precautions should be observed.

WARNING

Take all necessary safety precautions when installing the scale carriage including wearing safety shoes, protective eyewear, and using the proper tools.
Always turn off the power supply before any connection is made or removed.
Before welding, the power supply must be off and the connectors removed.

Important

The load cell is very sensitive to damage by welding. The welding ground clamp must be attached to the same side of the weigh frame where the welding is. When in doubt, remove the load cell(s).
Follow the recommendations given when the application is checked.
The belt conveyor must be installed in a stable and rigid area, free from vibrations.
The construction of the belt frame must be stiff enough to prevent torsion or bending at the maximum load (including the weight frame).
The weigh frame must be mounted free of mechanical tension.
No vibrations in the conveyor should be allowed to carry over to the weigh frame. If needed, these must be filtered.
The belt must be of good quality and a single splice. A vulcanized splice will provide the best accuracy. The weight per foot (meter) should be consistent over the whole length.
The belt must not track out of the center and no steering idler must be placed near the weighing area.
The belt support must not be supported with two-part (v-shape) idler stations.
At least three idler stations before and three idler stations after the weigh frame (the weighing section) have to be adjustable in height. For short belt conveyors this can be reduced to one roller before and one roller after the weighframe.
String alignment should be used on all idlers in the scale system. If following the rule of three before and three after, seven idlers (including the weigh idler) should be checked during the alignment process.
Rollers should not have a concentricity exceeding +/- 0.012 in (0.3 mm).
The speed sensor should be mounted on a non-driven roller or drum.
The inclination angle of the belt conveyor must not exceed 12%.
Proper covers may be required to prevent airflow from interfering with the belt scale.
Side guards and belt skirting should not be in contact with the weighing area of the belt scale.

Mechanical Installation

The mechanical installation of a belt scale consists of mounting the belt scale, the speed pickup, and the junction box. Three types of scale installation are included in this manual:

311 – a weigh frame that is made to order, lengths will vary.
311M – a modular weigh frame, the width can be adjusted in the field for smaller conveyors.
711 – a pivot weigh frame that is made to order, lengths will vary.

311/311M Installation
The 311/311M width can be adjusted slightly to fit across the stringers of the belt conveyor.

Note
The length of the 311M can be shortened, see Section 2.1.2 on page 6.

Determine the location for the belt scale. This location should be at least five idlers after the load point of the conveyor and at least five idlers before the head pulley.
Remove the belt from the selected area.
Remove the existing idler where the scale is to be located. $RICE-LAKE-311-Belt-Scale-fig- $1$$
Remove any mounting brackets that may be attached to the idler.
Adjust the weigh frame to fit between the conveyor frame stringers. To adjust the end brackets, loosen the bolts allowing the bracket to slide back and forth in the bracket slots. Ensure the length of the slots are sitting on the conveyor stringers.
Align the weigh frame mounting bracket slots with the holes used for anchoring the idler.
Use the existing hardware from the idler to secure the weigh frame to the conveyor stringers. $RICE-LAKE-311-Belt-Scale-fig- $3$$
Remove the idler clamps from the weigh frame assembly.
Place the idler on top of the weigh frame.
Place the idler clamps on the idler bottom stringer and secure it with bolts, washers, and nuts. $RICE-LAKE-311-Belt-Scale-fig- $4$$
Run strings on the conveyor (three before the scale and three past the scale) and shim the idlers to the same plane. $RICE-LAKE-311-Belt-Scale-fig- $5$$

Note Shims are not included with scale. They are available separately.

Adjusting 311M Length

Measure the distance between the stringers at the location selected for the belt scale. $RICE-LAKE-311-Belt-Scale-fig- $6$$
Remove the angle bracket, flat plate, and idler clamp from both ends of the weigh frame.
Using the measurement from step one determine how much needs to be cut off from the weighframe. Divide this number by two; this is the amount to be cut off from each end of the weigh frame.
Measure carefully from each end of the weigh frame to cut off the exact same amount on each side.
Important
Carefully measure each end of the weigh frame. The exact same amount must be removed from each side to ensure accurate weighing.
Reinstall the angle bracket, flat plate, and idler clamp to both ends of the weigh frame.
Proceed with installation.

711 Installation

Determine the location for the belt scale. This location should be at least five idlers after the load point of the conveyor and at least five idlers before the head pulley.
Remove the existing idler where scale is to be located. $RICE-LAKE-311-Belt-Scale-fig- $8$$
Remove any mounting brackets that may be attached to the idler.
Align the weigh frame mounting bracket slots with the holes used for anchoring the idler.
Use the existing hardware from the idler to secure the weigh frame to the conveyor stringers. $RICE-LAKE-311-Belt-Scale-fig- $9$$
Remove the idler clamps from the weigh frame assembly.
Place the idler on top of the weigh frame.
Place the idler clamps on the idler bottom stringer and secure it with bolts, washers, and nuts. $RICE-LAKE-311-Belt-Scale-fig- $10$$
Run strings on the conveyor (three before the scale and three past the scale) and shim the idlers to the same plane. See Figure 2-5.

Transport Lockout
The 711 is equipped with a transport lockout, to engage when the conveyor is being moved.

Transport Belt Scale

Loosen jam nut.
Turn transport bolts in to remove load from the load cell.
Tighten the jam nut so the bolt cannot change position.

To Use Belt Scale

Loosen jam nut.
Turn transport bolts out to allow load onto the load cell.
Tighten the jam nut so the bolt cannot change position.

Splice Box Installation

Mount the splice box in an appropriate location. $RICE-LAKE-311-Belt-Scale-fig- $12$$
Wire load cells according to the load cell data sheets.
Terminate the homerun cable at the splice box and integrator.
Calibrate the scale using the calibration procedure for the applicable integrator.

Electrical Installation

The wiring and connections between the weigh frame, speed pickup, and electronics are shown in the applicable scheme. See Section 3.3 on page 10.
The load cell is provided with a fixed cable; do not alter the length. If necessary, use an additional junction box with screw terminals to extend the cable length.

Cable Types

Load cell
If the length is more than 197 ft (60 m), use a shielded 6-wire cable 20 AWG gauge (0.5 mm²).

Speed pickup
Use shielded 3-wire cable 20 AWG gauge (0.5 mm²).

Cable shielding
The cable shielding must be connected to one side only. If connected to the instrument side, then it is preferred to use the same ground as the power supply.

Commissioning

Commissioning should be performed by service engineers who are trained and experienced with the subject.

Mechanical Adjustments
Mechanical adjustments must be made to ensure the scale is free of any tension. If necessary, the load cell can be adjusted.

Maintenance

Regular maintenance is essential to prevent errors or unnecessary downtime. The supplier does not accept any responsibility for the consequences of not performing the maintenance recommended in this section.

Maintenance

WARNING

It is important to ensure the safety of personnel during maintenance work and that no accidents will happen. Before any work on electrical systems is started, be sure to remove the main power supply.
The conveyor must be shut off before any work on the conveyor is started. Any goods on the conveyor must be removed first. No unauthorized persons are allowed in the conveyor’s working area.

Periodical Maintenance
To keep the belt scale in optimal condition, it is important to perform periodical maintenance.

Ensure there is not a build up of debris on the belt.
Inspect the weighframe for damaged areas and repair as necessary.
Regularly perform an Auto Zero and a weight check with certified test weights to determine if the belt scale weighs correctly. For this procedure, refer to the manual of the electronics installed.

Dimensional Drawings

$RICE-LAKE-311-Belt-Scale-fig- $13$$

Note

The 311 lengths will vary, they are made to order.
The length of the 311M can be shortened, see Section 2.1.2. $RICE-LAKE-311-Belt-Scale-fig- $14$$

Note The 711 lengths will vary, they are made to order.

Specifications

Standard

Weigh frame Material Powder coated mild steel or stainless steel SS304 / 316
weight approximately 104 lb (47 kg), not including the idler
Load Cell
- 1 potted single-point load cell
- Capacity 50 to 250 kg (each)
- Power supply 5-15 VDC (stabilized from electronics)
- Signal nominal 2 mV/V at 100% load

Total Load Cell Build
The Master 311/711 Series has a single load cell. Table 3-1 outlines the total load cell build, this value is used for the theoretical calibration.